Image forming apparatus having improved mountability of a cartridge while conserving space

ABSTRACT

In an image forming apparatus, a tray unit to which a cartridge is detachably mounted, and that is configured to be capable of moving between an internal position situated within the apparatus main body and an external position situated outside, includes first and second side plates configured to support the cartridge, and they are each made of metal, and include a supporting portion and an outer side portion, the supporting portions includes positioning portions configured to come into contact with the cartridge to position the cartridge as to an image forming position. The apparatus main body includes first and second pressing members each capable of moving between pressing positions at which the cartridge is pressed, and separated positions separated from the cartridge. The first and second pressing members are disposed each intersecting with imaginary planes that is orthogonal to the longitudinal direction and intersect the positioning portions.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an image forming apparatus that formsimages on recording material.

Description of the Related Art

There are image forming apparatuses, such as printers, photocopiers,multifunction peripherals, and so forth, in which a cartridge isdetachably mounted to a moving member that moves between the interiorand the exterior of an apparatus main body. Japanese Patent ApplicationPublication No. 2016-114620 discloses an image forming apparatus inwhich a cartridge is detachably mounted to a moving member that movesbetween the interior and the exterior of an apparatus main body. Themoving member in Japanese Patent Application Publication No. 2016-114620is provided with a metal reinforcement member.

SUMMARY OF THE INVENTION

The present invention is a further advancement of the conventionaltechnology. The present invention relates to an image forming apparatusincluding an apparatus main body, and a tray unit having a side plateformed of metal, to which a cartridge is detachably mounted, in whichthe tray unit is configured to be movable as to the apparatus main body.It is an object of the present invention to provide technology capableof improving mountability of the cartridge to the apparatus main bodyand conservation of space of the apparatus configuration.

In order to solve the above-described problem, an image formingapparatus according to the present invention, configured to performimage forming operations using a cartridge, includes:

an apparatus main body; and

a tray unit to which the cartridge is detachably mounted, and that isconfigured to be capable of moving with respect to the apparatus mainbody, between an internal position situated within the apparatus mainbody and an external position situated outside of the apparatus mainbody, the tray unit including:

-   -   a first side plate configured to support the cartridge, wherein        the first side plate is made of metal, and includes a first        supporting portion and a first outer side portion, the first        supporting portion includes a first positioning portion, and the        first positioning portion is configured to come into contact        with the cartridge to position the cartridge as to an image        forming position at which the image forming operation is        performed,    -   a second side plate configured to support the cartridge, wherein        the second side plate is made of metal, and includes a second        supporting portion and a second outer side portion, the second        supporting portion includes a second positioning portion, and        the second positioning portion is configured to come into        contact with the cartridge to position the cartridge as to the        image forming position, and    -   a mounting portion to which the cartridge is mounted in a        mounting direction, wherein the mounting portion is formed        between the first side plate and the second side plate, and, in        a case of being viewed in the mounting direction, the first        supporting portion and the second supporting portion are        situated between the first outer side portion and the second        outer side portion in the longitudinal direction of the        cartridge mounted to the mounting portion,

wherein the apparatus main body includes:

-   -   a first pressing member that is capable of moving between a        first pressing position at which the cartridge is pressed, and a        first separated position separated from the cartridge, and    -   a second pressing member that is capable of moving between a        second pressing position at which the cartridge is pressed, and        a second separated position separated from the cartridge,

wherein the first pressing member is disposed intersecting with a firstimaginary plane that is orthogonal to the longitudinal direction andintersects the first positioning portion,

and wherein the second pressing member is disposed intersecting with asecond imaginary plane that is orthogonal to the longitudinal directionand intersects the second positioning portion.

In order to solve the above-described problem, an image formingapparatus according to the present invention, configured to performimage forming operations using a cartridge, includes:

an apparatus main body; and

a tray unit to which the cartridge is detachably mounted, and that isconfigured to be capable of moving with respect to the apparatus mainbody, between an internal position situated within the apparatus mainbody and an external position situated outside of the apparatus mainbody, the tray unit including:

-   -   a first side plate configured to support the cartridge, wherein        the first side plate is made of metal, and includes a first        supporting portion and a first outer side portion, the first        supporting portion includes a first positioning portion, and the        first positioning portion is configured to come into contact        with the cartridge to position the cartridge as to an image        forming position at which the image forming operation is        performed,    -   a second side plate configured to support the cartridge, wherein        the second side plate is made of metal, and includes a second        supporting portion and a second outer side portion, the second        supporting portion includes a second positioning portion, and        the second positioning portion is configured to come into        contact with the cartridge to position the cartridge as to the        image forming position, and    -   a mounting portion to which the cartridge is mounted in a        mounting direction, wherein the mounting portion is formed        between the first side plate and the second side plate, and, in        a case of being viewed in the mounting direction, the first        supporting portion and the second supporting portion are        situated between the first outer side portion and the second        outer side portion in the longitudinal direction of the        cartridge mounted to the mounting portion,

wherein the tray unit has a tray contact configured to be electricallyconnected to a cartridge contact of the cartridge, the tray contacthaving a contact portion that comes into contact with the cartridgecontact,

and wherein the contact portion is situated between the secondsupporting portion and the second outer side portion in the longitudinaldirection.

In order to solve the above-described problem, an image formingapparatus according to the present invention, configured to performimage forming operations using a cartridge, includes:

an apparatus main body; and

a tray unit to which the cartridge is detachably mounted, and that isconfigured to be capable of moving with respect to the apparatus mainbody, between an internal position situated within the apparatus mainbody and an external position situated outside of the apparatus mainbody, the tray unit including:

-   -   a first side plate configured to support the cartridge, wherein        the first side plate is made of metal, and includes a first        supporting portion and a first outer side portion, the first        supporting portion includes a first positioning portion, and the        first positioning portion is configured to come into contact        with the cartridge to position the cartridge as to an image        forming position at which the image forming operation is        performed,    -   a second side plate configured to support the cartridge, wherein        the second side plate is made of metal, and includes a second        supporting portion and a second outer side portion, the second        supporting portion includes a second positioning portion, and        the second positioning portion is configured to come into        contact with the cartridge to position the cartridge as to the        image forming position, and    -   a mounting portion to which the cartridge is mounted in a        mounting direction, wherein the mounting portion is formed        between the first side plate and the second side plate, and, in        a case of being viewed in the mounting direction, the first        supporting portion and the second supporting portion are        situated between the first outer side portion and the second        outer side portion in the longitudinal direction of the        cartridge mounted to the mounting portion,

wherein the tray unit has a first guided groove and a second guidedgroove that are guided by the apparatus main body in case of moving fromthe external position to the internal position,

and wherein, with respect to the longitudinal direction, at least partof the first guided groove is situated between the first supportingportion and the first outer side portion, and at least part of thesecond guided groove is situated between the second supporting portionand the second outer side portion.

According to the present invention, mountability of the cartridge to theapparatus main body and conservation of space of the apparatusconfiguration can be improved.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overall perspective diagram illustrating a printeraccording to a first embodiment of the present disclosure;

FIG. 2 is an overall schematic diagram illustrating an internalconfiguration of the printer;

FIGS. 3A and 3B are a frontal perspective view and a rear perspectiveview illustrating a process cartridge;

FIGS. 4A and 4B are a frontal perspective view and a rear perspectiveview illustrating a cartridge tray;

FIGS. 5A and 5B are a frontal perspective view and a rear perspectiveview illustrating a cartridge tray in a state in which processcartridges are mounted;

FIGS. 6A and 6B are side views illustrating a driving side of thecartridge tray;

FIGS. 7A and 7B are side views illustrating a non-driving side of thecartridge tray;

FIG. 8 is a top view of the cartridge tray;

FIG. 9 is a perspective view illustrating a frame structure of a printermain body;

FIG. 10 is a bottom perspective view illustrating a positioning shaft ofthe cartridge tray;

FIG. 11A is a cross-sectional view illustrating a state in which apositioning shaft at an apparatus main body side is engaged with apositioning groove;

FIG. 11B is a cross-sectional view illustrating the positioning shaftand the positioning groove in a state in which the cartridge tray isslightly drawn out from the mounted state;

FIG. 11C is a cross-sectional view illustrating the positioning shaftand the positioning groove in a state in which the cartridge tray isfurther drawn out from the state in FIG. 11B;

FIG. 11D is a cross-sectional view illustrating a state in which thepositioning shaft of the cartridge tray side is engaged with thepositioning groove;

FIG. 11E is a cross-sectional view illustrating the positioning shaftand the positioning groove in a state in which the cartridge tray isslightly drawn out from the mounted state;

FIG. 11F is a cross-sectional view illustrating the positioning shaftand the positioning groove in a state in which the cartridge tray isfurther drawn out from the state in FIG. 11E;

FIG. 12 is a frontal view illustrating a rib provided to the cartridgetray;

FIG. 13 is a view along arrows A in FIG. 12 ;

FIG. 14A is a frontal perspective view of the process cartridges and thecartridge tray in a state in which a front door is closed;

FIG. 14B is a frontal perspective view of the process cartridges and thecartridge tray in a state in which the front door is open;

FIG. 15A is a rear perspective view of the process cartridges and thecartridge tray in a state in which the front door is closed;

FIG. 15B is a rear perspective view of the process cartridges and thecartridge tray in a state in which the front door is open;

FIG. 16A is a side view of the process cartridges and the cartridge trayin a state in which the front door is closed;

FIG. 16B is a side view of the process cartridges and the cartridge trayin a state in which the front door is open;

FIG. 16C is a side view of the process cartridges and the cartridge trayin a state in which the front door is open;

FIGS. 17A and 17B are diagrams illustrating a state in which thecartridge tray is drawn out;

FIGS. 18A through 18C are diagrams illustrating a pressing state at aleft side of the process cartridges and a contact state of contacts;

FIGS. 19A through 19C are diagrams illustrating a pressing state at aright side of the process cartridges; and

FIGS. 20A and 20B are diagrams illustrating a positional relationbetween a contact portion for power supply to a charging roller, and aphotosensitive drum and so forth.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, a description will be given, with reference to thedrawings, of embodiments (examples) of the present invention. However,the sizes, materials, shapes, their relative arrangements, or the likeof constituents described in the embodiments may be appropriatelychanged according to the configurations, various conditions, or the likeof apparatuses to which the invention is applied. Therefore, the sizes,materials, shapes, their relative arrangements, or the like of theconstituents described in the embodiments do not intend to limit thescope of the invention to the following embodiments. Each of theembodiments of the present invention described below can be implementedsolely or as a combination of a plurality of the embodiments or featuresthereof where necessary or where the combination of elements or featuresfrom individual embodiments in a single embodiment is beneficial.

First Embodiment Overall Configuration

First, a printer 100 serving as an image forming apparatus according toa first embodiment is a full-color laser beam printer according to anelectrophotographic system. The printer 100 has an apparatus main body100A and a front door 31 supported so as to be capable of opening andclosing as to the apparatus main body 100A, as illustrated in FIG. 1 .Note that directions are defined as follows in description of theprinter 100. That is to say, the side of the printer 100 on which thefront door 31 is provided is a front side (or front face side), and theopposite side therefrom is a back side (or rear face side), and thedirection from the back side toward the front side and the directionfrom the front side toward the back side is a front-back direction.

Also, a left side (or non-driving side) and a right side (or drivingside), and an upper side and a lower side are defined with a state ofviewing the printer 100 from the front side as a reference. Thedirection from the right side toward the left side and the directionfrom the left side toward the right side is a right-left direction, andthe direction from the lower side toward the upper side and thedirection from the upper side toward the lower side is an up-downdirection.

The printer 100 has an image forming unit 10 that forms images on sheetsS, a sheet feeding portion 18, a fixing device 23, a discharge rollerpair 24, and a control portion 200, as illustrated in FIG. 2 . Theprinter 100 can form full-color images or monochrome images onsheet-like recording media (hereinafter, referred to as “sheet S”), onthe basis of electrical image signals input to the control portion 200,output from an external host device 400 via an interface portion 300.Examples of the external host device 400 include a personal computer, animage reader, a facsimile apparatus, and so forth.

The control portion 200 is a control unit for controlling anelectrophotographic image forming process of the printer 100, andexchanges various types of electrical information with the external hostdevice 400. The control portion 200 also governs processing ofelectrical information input from various types of process devices andsensor, processing of command signals to various types of processdevices, predetermined initial sequence control, sequence control ofpredetermined image forming processes, and so forth.

The sheet feeding portion 18 is provided at a lower portion of theprinter 100, and includes a cassette 19 that accommodates the sheets S,a sheet plate 21 that supports the sheets S so as to be capable of beingraised and lowered, a pick-up roller 20 a, and a separating roller pair20 b. The cassette 19 is configured to be capable of being drawn out andmounted from the front side of the apparatus main body 100A. The sheetsS loaded on the sheet plate 21 are fed by the pick-up roller 20 a, andseparated into individual sheets by the separating roller pair 20 b.Note that a torque limiter system or a retard roller system may beapplied to the separating roller pair 20 b, and a separating pad may beapplied instead of one roller of the separating roller pair 20 b.

The fixing device 23 has a fixing film 23 a that is heated by a heater,and a pressure roller 23 b that presses against the fixing film 23 a,forming a fixing nip Q by the fixing film 23 a and the pressure roller23 b. The discharge roller pair 24 has a discharge driving roller 24 a,and a discharge driven roller 24 b that rotates following driving of thedischarge driving roller 24 a.

The image forming unit 10 has a cartridge tray 40, four processcartridges (cartridges) PPY, PPM, PPC, and PPK, a scanner unit 11, atransfer unit 12, and a cleaning unit 26. The transfer unit 12 has adriving roller 14, an auxiliary roller 15, a tension roller 16, and anintermediate transfer belt 13. The intermediate transfer belt 13 isstretched over the driving roller 14, the auxiliary roller 15, and thetension roller 16, is configured of a dielectric material, and hasflexibility. The printer 100 is configured to perform image formingoperations using the process cartridges PPY, PPM, PPC, and PPK that aredetachably mountable to the apparatus main body 100A.

Primary transfer rollers 17Y, 17M, 17C, and 17K that face the respectivephotosensitive drums of the process cartridges PPY, PPM, PPC, and PPKare provided on the inner side of the intermediate transfer belt 13. Asecondary transfer roller 27 is provided on the opposite side of thedriving roller 14 across the intermediate transfer belt 13. Theintermediate transfer belt 13 and the secondary transfer roller 27together form a secondary transfer nip T2.

The four process cartridges PPY, PPM, PPC, and PPK form toner images ofthe four colors of yellow (Y), magenta (M), cyan (C), and black (K),respectively. Note that the four process cartridges PPY, PPM, PPC, andPPK each have the same configuration, other than the color of imagesformed thereby (the color of toner accommodated) being different.Accordingly, the configuration and the image forming process will bedescribed regarding one of the four process cartridges PPY, PPM, PPC,and PPK, and description of the others will be omitted. Also, if thereis no need to distinguish among the process cartridges PPY, PPM, PPC,and PPK, the process cartridges PPY, PPM, PPC, and PPK may be referredto simply as “process cartridges PP”.

The process cartridge PPY has a drum unit OP and a developing unit DPintegrated into a unit, as illustrated in FIGS. 2 through 3B. The drumunit OP has a photosensitive drum 1 serving as an image bearing member,and the developing unit DP has a developing roller 3 that develops alatent image formed on the photosensitive drum 1 as a toner image, and astorage portion 3 b that stores a developer. A drum coupling (drivingtransmission member, first driving transmission member) 1 c and adeveloping coupling (driving transmission member, second drivingtransmission member) 3 c are each provided on the driving side (rightside) in the longitudinal direction of the photosensitive drum 1 and thedeveloping roller 3. Driving force from an unshown driving force sourceof the apparatus main body 100A is transmitted to the drum coupling 1 cand the developing coupling 3 c, and the photosensitive drum 1 and thedeveloping roller 3 rotate.

Also, a cartridge developing contact 2 is provided on the non-drivingside (left side) in the longitudinal direction of the developing roller3. Developing bias is applied to the cartridge developing contact 2, ina state of being in contact with a later-described main body developingcontact 38 (see FIG. 20B) provided to the apparatus main body 100A. Agrounding member (cartridge contact, cartridge electrode) 1 b forconnecting the photosensitive drum 1 to ground potential is provided atthe non-driving side in the longitudinal direction of the photosensitivedrum 1.

A drum bearing (driving side support member, first end portionsupporting member) 1 aR is provided to a driving side end portion (firstend portion) of the process cartridge PPY in the longitudinal directionof the process cartridge PPY, as illustrated in FIGS. 3A and 3B. A drumbearing (non-driving side support member, second end portion supportingmember) 1 aL is provided to a non-driving side end portion (second endportion) of the process cartridge PPY at the opposite side from thedriving side end portion. The drum bearing 1 aR and the drum bearing 1aL support the photosensitive drum 1.

Note that the longitudinal direction of the process cartridge PPY is thesame as the rotation axis direction (longitudinal direction) of thephotosensitive drum 1 and the rotation axis direction (longitudinaldirection) of the developing roller 3. When describing the apparatusmain body 100A and the cartridge tray 40 in the following description,the term “longitudinal direction of the process cartridge PPY” means thelongitudinal direction of the process cartridge PPY in a state mountedto a later-described mounting portion 40 a. In this case, thelongitudinal direction of the process cartridge PPY is the direction ofmovement of the cartridge tray 40, and is the direction orthogonal tothe direction of mounting the process cartridges PP in the presentembodiment.

The process cartridges PPY, PPM, PPC, and PPK, which are the pluralityof cartridges, are detachably mounted to the cartridge tray (tray unit,moving member, moving unit) 40. The cartridge tray 40 is configured tobe movable with respect to the apparatus main body 100A, between aninternal position situated within the apparatus main body 100A and anexternal position situated outside of the apparatus main body 100A, in astate of supporting the process cartridges PPY, PPM, PPC, and PPK, whichwill be described later. In the present embodiment, when the cartridgetray 40 is situated at the internal position, the process cartridgesPPY, PPM, PPC, and PPK are situated at image forming positions, andperform image forming operations. When the cartridge tray 40 is situatedat the external position, the process cartridges PPY, PPM, PPC, and PPKare situated at mounting/detaching positions, and can be mounted to ordetached from the cartridge tray 40.

The printer 100 is provided with the front door (opening/closing member)31 attached to the apparatus main body 100A. The front door 31 iscapable of moving between a closed position of covering the cartridgetray 40 at the internal position and an open position of exposing thecartridge tray 40 at the internal position. By the user opening thefront door 31, the cartridge tray 40 is exposed, and the user can accessthe cartridge tray 40. The user can then bring the process cartridgesPPY, PPM, PPC, and PPK to be situated at the mounting/detaching positionby drawing the cartridge tray 40 out to the front side, and can replacethe process cartridges PPY, PPM, PPC, and PPK.

Image Forming Operations

Next image forming operations of the printer 100 configured in this waywill be described. Upon the control portion 200 of the printer 100receiving job signals from the interface portion 300, an unshowndeveloping separating mechanism provided to the apparatus main body 100Amoves in the front-back direction. The developing separating mechanismbrings the developing roller 3 into contact with the photosensitive drum1.

Note that in a job of forming a monochrome image, only thephotosensitive drum of the process cartridge PPK comes into contact withthe developing roller, while in a job of forming a full-color image, thephotosensitive drums of the process cartridges PPY, PPM, PPC, and PPKcome into contact with the respective developing rollers. Thephotosensitive drums, the developing rollers, and the intermediatetransfer belt 13 are then driven by the unshown driving force source.

A scanner unit 11 casts a laser beam corresponding to image signals ontothe photosensitive drum 1 of the process cartridge PPY. The surface ofthe photosensitive drum 1 at this time is uniformly charged to apredetermined polarity and potential in advance by a charging member(charging roller) 5, and an electrostatic latent image is formed on thesurface by the laser being cast from the scanner unit 11. Theelectrostatic latent image formed on the photosensitive drum 1 isdeveloped by the developing roller 3, thereby forming a yellow (Y) tonerimage on the photosensitive drum 1.

Note that the cartridge tray 40 is provided with light guides 57 (seeFIG. 5B) as pre-exposing unit. The light guides 57 are each formed oftransparent acrylic or the like, for example. Light from an unshownlight source is emitted prior to the charging roller 5 charging thesurface of the photosensitive drum 1, and this light is cast on thesurface of the photosensitive drum 1 in a state of being uniformlydispersed in the longitudinal direction by the light guide 57.Accordingly, the potential at the surface of the photosensitive drum 1is stabilized, and good toner images can be formed.

In the same way, a laser beam is cast from the scanner unit 11 onto thephotosensitive drum in each of the process cartridges PPM, PPC, and PPK,and magenta (M), cyan (C), and black (K) toner images are formed on therespective photosensitive drums. The toner images of the respectivecolors formed on the respective photosensitive drums are transferredinto the intermediate transfer belt 13 by primary transfer bias appliedto the primary transfer rollers 17Y, 17M, 17C, and 17K. The full-colortoner image transferred onto the intermediate transfer belt 13 isconveyed to the secondary transfer nip T2 by the intermediate transferbelt 13 rotated by the driving roller 14. Note that the image formingprocesses of each of the colors are performed at timings for overlayingonto the toner image transferred upstream onto the intermediate transferbelt 13 by primary transfer.

In parallel with this image forming process, a sheet S sent out by thesheet feeding portion 18 is subjected to skew correction by aregistration roller pair 22. The registration roller pair 22 furtherconveys the sheet S toward the secondary transfer roller 27, inaccordance with the toner image being conveyed by the intermediatetransfer belt 13. The full-color toner image on the intermediatetransfer belt 13 is transferred onto the sheet S at the secondarytransfer nip T2, by the secondary transfer bias applied to the secondarytransfer roller 27. Also, after the transfer of the toner image, thetoner remaining on the surface of the intermediate transfer belt 13 isremoved by the cleaning unit 26, and is recovered to a waste tonerrecovery container that is omitted from illustration.

The sheet S onto which the toner image is transferred is subjected topredetermined heat and pressure at the fixing nip Q of the fixing device23. This causes the toner to melt, and subsequently be hardened, therebyfixing the image onto the sheet S. The sheet S that has passed throughthe fixing device 23 is discharged onto a discharge tray 25 by thedischarge roller pair 24.

Cartridge Tray

Next, the configuration of the cartridge tray 40 will be described. Thecartridge tray 40 has tray side plates 41L and 41R that are disposedwith a gap therebetween in the right-left direction, linking members 42,43, 44, 45, and 46 that link the tray side plates 41L and 41R to eachother, and guide members 47L and 47R, as illustrated in FIGS. 4A and 4B.Note that in the following description, members that are provided aspair of right and left members are distinguished regarding right andleft by appending “R” or “L” after the signs.

The process cartridges PPY, PPM, PPC, and PPK are supported by the trayside plates 41L and 41R. The mounting portions 40 a to which the processcartridges PPY, PPM, PPC, and PPK are mounted are formed between thetray side plate (driving-side side plate, first side plate) 41R and thetray side plate (non-driving-side side plate, second side plate) 41L.The process cartridge PPY is mounted to a mounting portion 40 aY, theprocess cartridge PPM is mounted to a mounting portion 40 aM, theprocess cartridge PPC is mounted to a mounting portion 40 aC, and theprocess cartridge PPK is mounted to a mounting portion 40 aK. Theprocess cartridges PPY, PPM, PPC, and PPK are mounted to the mountingportions 40 aY, 40 aM, 40 aC, and 40 aK, following the mountingdirection (the direction of arrow In).

The linking members 42, 43, 44, 45, and 46 are made of a resin material,and are arrayed in order from the front side toward the rear side. Theabove-described light guide 57 is provided to each of the linkingmembers 42, 43, 44, and 45. The tray side plates 41L and 41R are made ofa metal material. The guide member (driving side cover member, firstcover member) 47R is supported by the tray side plate 41R, and the guidemember (non-driving side cover member, second cover member) 47L issupported by the tray side plate 41L. The guide member 47R is providedwith a guide groove (first guided groove) 47 aR, and the guide member47L is provided with a guide groove (second guided groove) 47 aL. Theguide grooves 47 aL and 47 aR extend following the direction in whichthe plurality of cartridges are arrayed, and guide the cartridge tray 40in the direction of being draw out from, and the direction of beinginserted into, the apparatus main body 100A. The guide grooves 47 aL and47 aR also engage unshown stoppers provided to the apparatus main body100A, thereby restricting the cartridge tray 40 from being drawn outpast a predetermined position.

The linking member 42 has receiving portions 42 b and a gripping portion42 d. The user can draw the cartridge tray 40 out from the apparatusmain body 100A by gripping the gripping portion 42 d and pulling. Whenthe printer 100 is subjected to shock from the frontal direction in astate where the front door 31 is closed, the receiving portions 42 bsuppress damage of internal parts of the printer 100 caused by strikingthe front door 31. In the same way, the linking member 46 has receivingportions 46 a. When the printer 100 is subjected to shock from the reardirection, the receiving portions 46 a suppress damage of internal partsof the printer 100 caused by striking a fixing stay 35 (see FIG. 9 ).

The tray side plates 41L and 41R have shapes in which the upper portionsare drawn outwards as compared to the lower portions, with the distancebetween the tray side plates 41L and 41R in the right-left directionbeing greater at the upper portion and smaller at the lower portion.Thus, the right-left width of the cartridge tray 40 can be reducedwithout impeding the ease of insertion/extraction of the processcartridges PPY, PPM, PPC, and PPK, thereby contributing to reduction insize of the printer 100.

Further, the lower sides of the tray side plates 41L and 41R are bentinto a shape of the letter L, thereby ensuring strength. Although thetray side plates 41L and 41R and the linking members 42, 43, 44, 45, and46 are each fastened by screws, this is not restrictive, and thermalcaulking or the like may be used. Also, an arrangement may be made inwhich the linking members 42 and 46 alone are fastened to the tray sideplates 41L and 41R, and the linking members 43, 44, and 45 are notfastened to the tray side plates 41L and 41R.

The tray side plate 41R is provided with cartridge engaging portions(first positioning portion) 41 gR, 41 hR, 41 iR, and 41 jR, thecartridge engaging portions 41 gR, 41 hR, 41 iR, and 41 jR each beingformed having a substantially V-shaped form, as illustrated in FIGS. 4Athrough 5B. Specifically, the cartridge engaging portions 41 gR, 41 hR,41 iR, and 41 jR are formed so that front-side inclined faces thereofare at a 65° angle as to the direction of drawing out, and rear-sideinclined faces thereof are at a 45° angle.

The tray side plate 41L is provided with cartridge engaging portions(second positioning portion) 41 gL, 41 hL, 41 iL, and 41 jL, thecartridge engaging portions 41 gL, 41 hL, 41 iL, and 41 jL being formedhaving substantially V-shaped forms, as illustrated in FIG. 4A.Specifically, the cartridge engaging portions 41 gL, 41 hL, 41 iL, and41 jL are formed so that front-side inclined faces thereof are at a 65°angle as to the direction of drawing out, and rear-side inclined facesthereof are at a 45° angle.

The process cartridges PPY, PPM, PPC, and PPK are positioned by thecartridge tray 40 at image forming positions to perform image formingoperations. While image forming operations are performed, the drumbearing 1 aR (see FIG. 3A) of the process cartridge PPY comes intocontact with the cartridge engaging portion 41 gR, and the drum bearing1 aL (see FIG. 3B) of the process cartridge PPY comes into contact withthe cartridge engaging portion 41 gL. In the same way, the drum bearings1 aR of the process cartridges PPM, PPC, and PPK come into contact withthe cartridge engaging portions 41 hR, 41 iR, and 41 jR. Also, the drumbearings 1 aL of the process cartridges PPM, PPC, and PPK come intocontact with the cartridge engaging portions 41 hL, 41 iL, and 41 jL.That is to say, the cartridge engaging portion 41 gR and the cartridgeengaging portion 41 gL come into contact with and support the drumbearing 1 aR and the drum bearing 1 aL of the process cartridge PPY, sothat the process cartridge PPY is positioned at the image formingposition. In the same way, the cartridge engaging portions 41 hR, 41 iR,and 41 jR and the cartridge engaging portions 41 hL, 41 iL, and 41 jLcome into contact with and support the drum bearings 1 aR and the drumbearings 1 aL of the process cartridges PPM, PPC, and PPK.

The process cartridges PPY, PPM, PPC, and PPK are positioned as to thecartridge tray 40, either under their own weight, or be being presseddownward by pressing units 33 and 34 (first pressing member 34, secondpressing member 33) (FIGS. 14A through 20B). The pressing units 33 and34 position the process cartridges, and the cartridge tray 40 that isintegral with the process cartridges, as to the apparatus main body100A, by pressing the process cartridges in the downward direction atthe time of forming images. The pressing units 33 and 34 are assembledto the apparatus main body 100A so as to be capable of moving between apressing position of pressing the process cartridges and a separatedposition of being separated from the process cartridges, ininterrelation with opening and closing actions of the front door 31 ofthe printer 100, which will be described later in detail.

Also, boss portions 42 aL, 43 aL, 44 aL, and 45 aL are respectivelyformed to the left end portions of the linking members 42, 43, 44, and45, and boss portions 42 aR, 43 aR, 44 aR, and 45 aR are respectivelyformed to the right end portions thereof. Note that groove portions 1 dRand 1 dL are formed on the right and left end portions of the processcartridges for each of the colors, as illustrated in FIGS. 3A and 3B.The groove portions 1 dR and 1 dL of the process cartridges PPY, PPM,PPC, and PPK then engage the boss portions 42 aL, 43 aL, 44 aL, and 45aL at the left end side, and engage the boss portions 42 aR, 43 aR, 44aR, and 45 aR at the right end side. Thus, the process cartridges PPY,PPM, PPC, and PPK are suppressed from rotating as to the cartridge tray40.

Thus, the process cartridges PPY, PPM, PPC, and PPK are mounted to thecartridge tray 40, and each process cartridge is grounded by a wiremember (drum ground) 48 provided to the guide member 47L.

Details of Cartridge Tray

Details of the cartridge tray 40 will be described with reference toFIGS. 6A through 8 . FIGS. 6A and 6B are side views illustrating thedriving side of the cartridge tray 40. FIGS. 6A and 6B are diagramsviewing the cartridge tray 40 along the longitudinal direction of theprocess cartridge PPY, and the guide member 47R is not illustrated inFIG. 6B. FIGS. 7A and 7B are side views illustrating the non-drivingside of the cartridge tray 40. FIGS. 7A and 7B are diagrams viewing thecartridge tray 40 along the longitudinal direction of the processcartridge PPY, and the guide member 47L is not illustrated in FIG. 7B.FIG. 8 is a top view of the cartridge tray 40. FIG. 8 is a diagramviewing the cartridge tray 40 along the mounting direction In of theprocess cartridges PPY, PPM, PPC, and PPK.

The tray side plate 41R is provided with a first supporting portion 41R1that has the cartridge engaging portions 41 gR, 41 hR, 41 iR, and 41 jR,a first outer side portion 41R2, and a first connecting portion 41R3that connects the first supporting portion 41R1 and the first outer sideportion 41R2, as illustrated in FIG. 6B. The tray side plate 41R is madeof metal. In the present embodiment, the tray side plate 41R is onemetal plate, and is integrally provided with the first supportingportion 41R1, the first outer side portion 41R2, and the firstconnecting portion 41R3. The first supporting portion 41R1 and the firstouter side portion 41R2 extend following the moving direction in whichthe cartridge tray 40 moves as to the apparatus main body 100A.

The tray side plate 41R is formed by drawing on a metal plate. As aresult, the first connecting portion 41R3 has a portion situated betweenthe first supporting portion 41R1 and the first outer side portion 41R2in the horizontal direction, and a portion situated between the firstsupporting portion 41R1 and the first outer side portion 41R2 in thevertical direction, as viewed in the longitudinal direction of theprocess cartridge PPY. Further, the tray side plate 41R is provided withfirst openings 41R5. The cartridge engaging portions 41 gR, 41 hR, 41iR, and 41 jR are formed in the first openings 41R5. The upper end ofthe first openings 41R5 is situated higher than the lower end of thefirst outer side portion 41R2, and the lower end of the first openings41R5 is situated lower than the upper end of the first supportingportion 41R1 and the first connecting portion 41R3, with respect to thevertical direction. The process cartridges PPY, PPM, PPC, and PPK areexposed to the outside of the mounting portions 40 a through the firstopenings 41R5. More specifically, the drum couplings 1 c of the processcartridges PPY, PPM, PPC, and PPK are externally exposed from thecartridge tray 40 through the first openings 41R5.

As illustrated in FIG. 6A, the cartridge tray 40 has the guide member(first cover member) 47R that is attached to the tray side plate 41R onthe outer side of the mounting portions 40 a. The guide member 47Rcovers the first supporting portion 41R1. More specifically, the guidemember 47R covers the first supporting portion 41R1 such that thecartridge engaging portions 41 gR, 41 hR, 41 iR, and 41 jR are exposedwhen viewed in the longitudinal direction of the process cartridge PPY.

Also, as described above, the guide member 47R is provided with theguide groove (first guided groove) 47 aR. The guide groove 47 aR issituated on the downstream side of the cartridge engaging portions 41gR, 41 hR, 41 iR, and 41 jR in the mounting direction In of the processcartridges PPY, PPM, PPC, and PPK. The guide groove 47 aR extends in thedirection in which the process cartridges PPY, PPM, PPC, and PPK arearrayed. Accordingly, the cartridge tray 40 is capable of moving as tothe apparatus main body 100A in the direction in which the processcartridges PPY, PPM, PPC, and PPK are arrayed.

The tray side plate 41L is provided with a second supporting portion41L1 that has the cartridge engaging portions 41 gL, 41 hL, 41 iL, and41 jL, a second outer side portion 41L2, and a second connecting portion41L3 that connects the second supporting portion 41L1 and the secondouter side portion 41L2, as illustrated in FIG. 7B. The tray side plate41L is made of metal. In the present embodiment, the tray side plate 41Lis one metal plate, and is integrally provided with the secondsupporting portion 41L1, the second outer side portion 41L2, and thesecond connecting portion 41L3. The second supporting portion 41L1 andthe second outer side portion 41L2 extend along the moving direction inwhich the cartridge tray 40 moves as to the apparatus main body 100A.

The tray side plate 41L is formed by drawing on a metal plate. As aresult, the second connecting portion 41L3 has a portion situatedbetween the second supporting portion 41L1 and the second outer sideportion 41L2 in the horizontal direction, and a portion situated betweenthe second supporting portion 41L1 and the second outer side portion41L2 in the vertical direction, as viewed in the longitudinal directionof the process cartridge PPY. Further, the tray side plate 41L isprovided with second openings (contact openings) 41L5. The cartridgeengaging portions 41 gL, 41 hL, 41 iL, and 41 jL are formed in thesecond openings 41L5. The upper end of the second openings 41L5 issituated higher than the lower end of the second outer side portion41L2, and the lower end of the second openings 41L5 is situated lowerthan the upper end of the second supporting portion 41L1 and the secondconnecting portion 41L3, with respect to the vertical direction. Theprocess cartridges PPY, PPM, PPC, and PPK are exposed to the outside ofthe mounting portions 40 a through the second openings 41L5. Morespecifically, the grounding members 1 b of the process cartridges PPY,PPM, PPC, and PPK are externally exposed from the mounting portions 40 athrough the second openings 41L5.

As illustrated in FIG. 7A, the cartridge tray 40 has the guide member(second cover member) 47L that is attached to the tray side plate 41L onthe outer side of the mounting portions 40 a. The guide member 47Lcovers the second supporting portion 41L1. More specifically, the guidemember 47L covers the second supporting portion 41L1 such that at leastpart of the second openings 41L5 is covered as viewed in thelongitudinal direction of the process cartridge PPY. The guide member47L is also provided with the wire members 48. The wire members 48 aredisposed at positions that overlap the second openings 41L5 as viewed inthe longitudinal direction of the process cartridge PPY.

Also, the guide member 47L is provided with the guide groove (secondguided groove) 47 aL, as described above. The guide groove 47 aL issituated on the downstream side of the cartridge engaging portions 41gL, 41 hL, 41 iL, and 41 jL in the mounting direction In of the processcartridges PPY, PPM, PPC, and PPK. The guide groove 47 aL extends in thedirection in which the process cartridges PPY, PPM, PPC, and PPK arearrayed. Accordingly, the cartridge tray 40 is capable of moving as tothe apparatus main body 100A in the direction in which the processcartridges PPY, PPM, PPC, and PPK are arrayed.

As illustrated in FIG. 8 , when viewed in the mounting direction In, thefirst supporting portions 41R1 and the second supporting portions 41L1are situated between the first outer side portion 41R2 and the secondouter side portion 41L2 in the longitudinal direction (arrow LD) of theprocess cartridges PP mounted to the mounting portion 40 a. Also, whenviewed in the mounting direction In, the cartridge engaging portions 41gR, 41 hR, 41 iR, and 41 jR are exposed to the upstream side (near sidein the plane of the figure) in the mounting direction In via the firstopenings 41R5. In the same way, the cartridge engaging portions 41 gL,41 hL, 41 iL, and 41 jL are exposed to the upstream side (near side inthe plane of the figure) in the mounting direction In via the secondopenings 41L5.

Positioning Configuration of Cartridge Tray

Next, a positioning configuration of the cartridge tray 40 will bedescribed. The apparatus main body 100A (see FIG. 1 ) has a main bodyframe 30 having a pair of left and right main body side plates 36L and36R, the fixing stay 35 that links the main body side plates 36L and 36Rand also compartmentalizes a process region and a fixing region, asillustrated in FIG. 9 . The process region is a region where the processcartridges PPY, PPM, PPC, and PPK are accommodated, and the fixingregion is a region where the fixing device 23 is accommodated. The mainbody side plates 36L and 36R and the fixing stay 35 are made of a metalmaterial.

The main body side plates 36L and 36R have shaft supporting portions 50aL and 50 aR, respectively, at the deep side of the apparatus, with apositioning shaft 50 being supported by the shaft supporting portions 50aL and 50 aR. Note that the positioning shaft 50 is immovably fixed tothe shaft supporting portions 50 aL and 50 aR, but may be rotatablysupported as long as it is not capable of moving in the front-backdirection and the up-down direction.

The main body side plates 36L and 36R also have positioning grooves 36aL and 36 aR respectively, at the apparatus front side thereof. Shaftsupporting portions 41 dL and 41 dR are respectively formed at the frontside of the tray side plates 41L and 41R of the cartridge tray 40, asillustrated in FIG. 10 . A positioning shaft 49 is supported by theshaft supporting portions 41 dL and 41 dR. The positioning shaft 49passes through the tray side plates 41L and 41R, with a left-side endportion 49 a and right-side end portion (omitted from illustration) ofthe positioning shaft 49 protruding to the outer side of the tray sideplates 41L and 41R. Note that the positioning shaft 49 is immovablyfixed to the shaft supporting portions 41 dL and 41 dR, but may berotatably supported as long as it is not capable of moving in thefront-back direction and the up-down direction. Also, the positioningshafts 49 and 50 are configured of round rod-shaped shafts that extendin the right-left direction and have a circular cross-sectional shape,but the shapes thereof are not limited.

A shaft contact portion 42 c that supports the substantially middleportion of the positioning shaft 49 in the axial direction from beneathis formed on the linking member 42. The shaft contact portion 42 crestricts downward deflection of the positioning shaft 49. Note that theshaft contact portion 42 c is not limited to being at the substantiallymiddle portion in the axial direction of the positioning shaft 49 andmay support the positioning shaft 49 from below at another position.However, restricting downward deflection of the positioning shaft 49 atthe middle portion of the positioning shaft 49 is suitable. Also, theshaft contact portion 42 c maybe formed long in the axial direction.

The positioning groove 36 aR of the main body side plate 36R is formedfollowing the insertion direction Y1 of the cartridge tray 40, and has afitting groove 37 aR formed at the deep side, and a guide groove 37 bRformed at the near side, as illustrated in FIG. 11D.

The fitting groove 37 aR has a width that is the same as or slightlysmaller than the outer diameter of the positioning shaft 49, and fits tothe end portion 49 a of the positioning shaft 49 when the cartridge tray40 is situated at a mounted position. The guide groove 37 bR has a widththat is larger than the outer diameter of the positioning shaft 49, andguides the end portion 49 a of the positioning shaft 49 to the fittinggroove 37 aR when mounting the cartridge tray 40 to the apparatus mainbody 100A. Note that a guide groove and a fitting groove are formed inthe same way for the main body side plate 36L, and guide and fit theleft-side end portion of the positioning shaft 49.

Positioning grooves 41 bL and 41 bR are respectively formed at thedeep-sides of the tray side plates 41L and 41R, as illustrated in FIG.5B. The positioning grooves 41 bL and 41 bR position the cartridge tray40 by engaging the positioning shaft 49. FIGS. 11A through 11C areenlarged views illustrating the positioning groove 41 bR. Note thatsince the positioning grooves 41 bL and 41 bR are of the sameconfiguration, description will be made regarding the positioning groove41 bR alone, and description of the positioning groove 41 bL will beomitted.

The positioning groove 41 bR has an inclined face 41 f, and apositioning face 41 e formed continuing from the inclined face 41 f, asillustrated in FIGS. 11A through 11C. The positioning face 41 e extendsin a direction substantially perpendicular to the insertion direction Y1of the cartridge tray 40, and positions the cartridge tray 40 in theinsertion direction by abutting the positioning shaft 50. The inclinedface 41 f inclines downward toward the insertion direction Y1. Also, asliding face 46 d (see FIG. 5B) is formed on the linking member 46 ofthe cartridge tray 40, with the sliding face 46 d being formed tocontinue from the inclined face 41 f to the near side.

When the cartridge tray 40 is mounted, the inclined face 41 f issubjected to reactive force F1 from the positioning shaft 50 due todownward force being applied from the own weight of the cartridge tray40 and the pressing units 33 and 34 (see FIG. 14A), as illustrated inFIG. 11A. The reactive force F1 contains component force of theinsertion direction Y1, and accordingly the cartridge tray 40 is drawninward in the insertion direction Y1, and moves in a direction F2. Thus,the positioning face 41 e is pressed against the positioning shaft 50,and can precisely position the cartridge tray 40 as to the apparatusmain body 100A. In this way, the inclined face 41 f is formed togenerate component force.

The positioning shaft 50 is supported by the shaft supporting portions50 aL and 50 aR of the main body side plates 36L and 36R, as illustratedin FIG. 12 . In a state in which the cartridge tray 40 is mounted to theapparatus main body 100A, the positioning grooves 41 bL and 41 bR aresituated on an inner side from the shaft supporting portions 50 aL and50 aR in the axial direction. Accordingly, the middle portion of thepositioning shaft 50 may exhibit downward (direction of outline arrow inFIG. 12 ) deflection under downward force from the own weight of thecartridge tray 40 and the pressing units 33 and 34 (see FIG. 14A).

Accordingly, a rib 46 b is formed at the substantially middle portion ofthe linking member 46 in the axial direction (right-left direction) inthe present embodiment. The rib 46 b restricts downward deflection ofthe positioning shaft 50 by coming into contact with the substantiallymiddle portion of the positioning shaft 50 in the axial direction andsupporting from below. Note that the rib 46 b is not limited to being atthe substantially middle portion of the positioning shaft 50 in theaxial direction and may support the positioning shaft 50 from below atanother position thereof. However, restricting downward deflection ofthe positioning shaft 50 at the middle portion of the positioning shaft50 is suitable. Also, the rib 46 b may be formed long in the axialdirection, or a plurality of ribs 46 b may be provided along the axialdirection. Also, although downward deflection is restricted in thepresent embodiment, since the positioning shaft 50 is subjected to forcein the gravitational direction. However, the arrangement does not haveto come into contact with the lower portion of the positioning shaft 50,as long as force in a direction of deflection of the positioning shaft50 is received and deflection of the positioning shaft 50 is restricted.

Also, retaining portions 46 c arranged to retain the fixing stay 35 areformed on the linking member 46, as illustrated in FIGS. 12 and 13 . Theretaining portions 46 c can restrict downward deflection of thecartridge tray 40 including the linking member 46 by retaining thefixing stay 35. Suppressing downward deflection of the cartridge tray 40also suppresses deformation of the cartridge tray 40 at the positioninggrooves 41 bL and 41 bR, and the cartridge tray 40 can be preciselypositioned as to the positioning shaft 50. Note that just one retainingportion 46 c, or three or more retaining portions 46 c may be providedwithout impeding the mounting operations of the cartridge tray 40. Also,one retaining portion 46 c may be formed long in the axial direction(right-left direction).

Operations of Drawing Out and Mounting Cartridge Tray

Next, the operations of drawing out and mounting the cartridge tray 40will be described. Once the developer in the process cartridges PPY,PPM, PPC, and PPK has been consumed to a degree where images of qualitythat satisfy the purchasing user can no longer be formed, the productvalue as process cartridges is lost.

Accordingly, an arrangement may be made in which unit (omitted fromillustration) detecting remaining developer amount of each of theprocess cartridges is provided, for example, and the control portion 200compares detected remaining amount values with threshold values set inadvance, for cartridge lifespan notices and lifespan warnings. In thisarrangement, a display regarding lifespan notice or lifespan warningregarding that process cartridge is displayed on a display portion(omitted from illustration) regarding process cartridges of which thedetected remaining amount value is a remaining amount value below thethreshold value, prompting the user to replace the process cartridge.The user thereupon opens the front door 31 of the printer 100, draws outthe cartridge tray 40 to the outside of the apparatus, and replaces theprocess cartridges PPY, PPM, PPC, and PPK. Operations of drawing out andmounting the cartridge tray 40 will be described below in detail.

The front door 31 is supported so as to be capable of opening andclosing as to the apparatus main body 100A, as illustrated in FIGS. 14Athrough 15B. The opened state can be maintained by door links 32L and32R linking between the front door 31 and the apparatus main body 100A.

When the user opens the front door 31, the transfer unit 12 rotatesaround 1° centered on the driving roller 14, by a plurality of linkmembers that are omitted from illustration cooperatively moving via thedoor links 32L and 32R. Accordingly, the photosensitive drums 1 of theprocess cartridges are separated from the intermediate transfer belt 13,as illustrated in FIG. 16C.

Next, the main body developing contacts 38 provided to the left side(non-driving side) of the apparatus main body 100A are retracted fromthe cartridge developing contacts 2 electrically connected to thedeveloping rollers 3 (see FIG. 3B), and pressure of the pressing units33 and 34 is released, as illustrated in FIG. 20B. That is to say, thepressing unit 33 serving as a second pressing member moves from a secondpressing position to a second separated position, and also the pressingunit 34 serving as a first pressing member moves from a first pressingposition to a first separated position. Next, engagement of the drumcouplings 1 c at the driving side of the process cartridges and thedeveloping couplings 3 c (FIG. 3A) is disengaged, and also pressing ofthe cartridge tray 40 by tray pressing units 51 is released, asillustrated in FIGS. 14B and 16B. As a result, the cartridge tray 40 isin a state in which it can be removed to the outside of the apparatusmain body 100A.

Now, the tray pressing units 51 are provided to each of holders 52L and52R supported by the main body side plates 36L and 36R, and press thecartridge tray 40 toward the front side from the back side, when formingimages. The tray pressing units 51 each has a tray pressing lever 53, atray pressing link 54, and a biasing spring (omitted from illustration),as illustrated in FIGS. 16A and 16B.

The tray pressing lever 53 is pressed by the tray pressing link 54 thatis biased by the biasing spring in a state in which the front door 31 isclosed as illustrated in FIG. 16A. Thus, the tray pressing lever 53presses a pressed portion 41 c formed on the tray side plate 41R of thecartridge tray 40 rearward.

When the front door 31 is opened, the tray pressing lever 53 isretracted downward by the door links 32L and 32R, and by a link memberthat is omitted from illustration as illustrated in FIG. 16B.Accordingly, pressure of the tray pressing lever 53 toward the rear sideof the cartridge tray 40 is released, and the cartridge tray 40 can beremoved to the outside of the apparatus main body 100A.

Next, the movements of members in the proximity of the positioningshafts 49 and 50 will be described with reference to FIGS. 11A through11F. Note, however, that the positioning configurations of the cartridgetray 40 regarding the positioning shafts 49 and 50 are the same on theright and left sides, and accordingly description will be made readingonly the right side of the apparatus, and description of the left sideof the apparatus will be omitted. When drawing out of the cartridge tray40 is started, the inclined face 41 f slides with respect to thepositioning shaft 50, and accordingly the deep side of the cartridgetray 40 is raised slightly as illustrated in FIGS. 11A through 11F. Thecartridge tray 40 then moves in a drawing out direction Y2 with thesliding face 46 d provided to the linking member 46 of the cartridgetray 40 sliding with respect to the positioning shaft 50.

At the same time, the end portion 49 a of the positioning shaft 49 ofthe cartridge tray 40 exits the fitting groove 37 aR of the positioninggroove 36 aR, and is handed over to the guide groove 37 bR. Thecartridge tray 40 is drawn out in the drawing out direction Y2, with theend portion 49 a of the positioning shaft 49 being guided by the guidegroove 37 bR. FIGS. 11A and 11D illustrate a state in which thecartridge tray 40 is situated at the mounted position. FIGS. 11B and 11Eillustrate a state in which the cartridge tray 40 is drawn out around 3mm from the mounted position. FIGS. 11C and 11F illustrate a state inwhich the cartridge tray 40 is drawn out around 10 mm from the mountedposition.

When the cartridge tray 40 is drawn out to a certain degree, thecartridge tray 40 rides on and is guided by rollers 56L and 56R (firstrotating member and second rotating member), as illustrated in FIGS. 14Band 15B. The cartridge tray 40 is thus drawn out to the outside of theapparatus main body 100A. Note when forming images, the cartridge tray40 and the rollers 56L and 56R are not in contact with each other, and aclearance of around 0.5 mm is secured therebetween.

FIGS. 17A and 17B are diagrams illustrating the process of the cartridgetray being drawn out. The guide groove 47 aL of the cartridge tray 40 isguided by a guide portion 32 aL provided to the door link 32L. Theconfigurations of the guide groove 47 aR and a guide portion 32 aR arethe same as the configurations of the guide groove 47 aL and the guideportion 32 aL. Accordingly, even in cases in which the amount of drawingout of the cartridge tray 40 is great, the cartridge tray 40 can besmoothly drawn out, with inclination reduced. Also, the attitude of thecartridge tray 40 when being drawn out can be stabilized, therebyfacilitating replacement of process cartridges.

The guide grooves 47 aL and 47 aR are formed as open-box shapes openingtoward the outer side, provided on the outer side of the firstsupporting portion 41R1 and the second supporting portion 41L1 of thetray side plates 41L and 41R made of a metal material. Protrudingportions 41L4 and 41R4 (first protruding portion and second protrudingportion) extending toward the outer side from the first supportingportion 41R1 and the second supporting portion 41L1 are disposed belowthe guide grooves 47 aL and 47 aR. The guide grooves 47 aL and 47 aR aredisposed between the outer side portions 41L2 and 41R2 and theprotruding portions 41L4 and 41R4. In the mounting direction of theprocess cartridges to the cartridge tray 40, the guide groove 47 aL isdisposed on the downstream side of the cartridge engaging portions 41gL, 41 hL, 41 iL, and 41 jL, and the guide groove 47 aR is disposed onthe downstream side of the cartridge engaging portions 41 gR, 41 hR, 41iR, and 41 jR. Thus, a power guide can be configured. When the cartridgetray 40 is drawn out, the protruding portions 41L4 and 41R4 aresupported riding on the rollers 56L and 56R.

Also, the guide grooves 47 aL and 47 aR are provided on the inner sidesfrom the first outer side portion 41R2 and the second outer side portion41L2 in the longitudinal direction of the photosensitive drum 1, and atleast part thereof is situated between the first supporting portion 41R1and the first outer side portion 41R2, and between the second supportingportion 41L1 and the second outer side portion 41L2, respectively, inthe longitudinal direction. Accordingly, layout thereof is realizedwithout increasing the size of the cartridge tray 40 and the imageforming apparatus. The process cartridges can be mounted to thecartridge tray 40 by dropping the process cartridges in through theopening spreading outward at the top of the cartridge tray 40. The trayside plates 41L and 41R are provided with the first connecting portion41R3 and the second connecting portion 41L3 that connect between thefirst supporting portion 41R1 and the second supporting portion 41L1,and the first outer side portion 41R2 and the second outer side portion41L2. The first connecting portion 41R3 and the second connectingportion 41L3 have inclined faces that incline from the outer side of themounting portion 40 a toward the inner side, with respect to thelongitudinal direction LD. More specifically, the inclined faces of thefirst connecting portion 41R3 and the second connecting portion 41L3incline from the outer side of the mounting portion 40 a toward theinner side, from the upstream side toward the downstream side in themounting direction of the process cartridges PP. These inclined facesenable the process cartridges PP to be smoothly mounted to the cartridgetray 40.

The mounted process cartridges PP are positioned by the cartridgeengaging portions 41 gL, 41 hL, 41 iL, 41 jL, 41 gR, 41 hR, 41 iR, and41 jR of the tray side plates 41L and 41R. At this time, the groundingmembers 1 b that are the cartridge contacts provided at the end portionsof the photosensitive drums 1 come into contact with the wire members 48that are contact members provided to the cartridge tray 40 for each ofthe process cartridges PP. The wire members 48 serve as intermediatecontacts that electrically connect the photosensitive drums 1 and themain body frame 30 of the apparatus main body 100A, as tray contacts.The wire members 48 come into contact with a conducting line 59 belowthe cartridge engaging portions 41 gL, 41 hL, 41 iL, and 41 jL, and areconnected to the main body side plate 36L of the main body frame 30 viathe conducting line 59. That is to say, when the cartridge tray 40 is atthe internal position of the apparatus main body 100A, the groundingmembers 1 b are electrically connected to the apparatus main body 100Avia the wire members 48 and the side plate 41L.

The wire members 48 each have an arm portion 48 b that serves as aspring portion having spring properties, and a wound portion 48 a woundfollowing the insertion direction In of the process cartridges PP at acontact portion with the grounding member 1 b. The wound portion 48 a isbiased toward the side of the grounding member 1 b by the springproperties of the arm portion 48 b. The grounding member 1 b and thewound portion 48 a come into contact at a position on the upstream sideof the cartridge engaging portions 41 gL, 41 hL, 41 iL, and 41 jL andthe downstream side of the second outer side portion 41L2 in thedirection of mounting the process cartridges to the cartridge tray 40.Meanwhile, the wound portion 48 a is roughly positioned by a contactrestricting portion 47 eL provided to the guide member 47L beinginserted into and passing through the wound portion 48 a. Due to thiscontact restricting portion 47 eL, the contact position of the groundingmember 1 b and the wound portion 48 a is restricted to a predeterminedposition, even when no process cartridge is mounted to the mountingportion 40 a. Further, by the wire members 48 being disposed lower thanthe second connecting portion 41L3, damage of the wire members 48 can besuppressed when inserting the process cartridges PP into the cartridgetray 40, and insertion of the process cartridges PP can be smoothlycarried out. Also, by disposing the wire members 48 on the inner sidefrom the second outer side portion 41L2 in the longitudinal direction ofthe photosensitive drums 1, layout thereof is realized withoutincreasing the size of the cartridge tray 40 and the image formingapparatus.

The wire members 48 are disposed adjacent to the outer side of thesecond supporting portion 41L1 of the tray side plate 41L in thelongitudinal direction of the photosensitive drums 1, and further theguide member 47L having the guide groove 47 aL is provided on the outerside, thereby holding the wire members 48. The wire members 48 are alsoelectrically connected to the tray side plate 41L that is made of ametal material, and as described later, the tray side plate 41L and thepositioning shafts 49 and 50 are connected, and the positioning shafts49 and 50 and the main body frame 30 are connected. Thus, a sturdygrounding contact path is formed.

When the cartridge tray 40 is drawn out and process cartridges arereplaced, the cartridge tray 40 is mounted to the apparatus main body100A. The mounting operation at the time of mounting the cartridge tray40 to the apparatus main body 100A is reverse to the operations ofdrawing out. At this time, the sliding face 46 d first begins slidingwith respect to the positioning shaft 50, and after the positioningshaft 50 moves beyond the sliding face 46 d, the end portion 49 a of thepositioning shaft 49 is handed over from the guide groove 37 bR to thefitting groove 37 aR, as illustrated in FIGS. 11B and 11E.

The boundary portion between the guide groove 37 bR and the fittinggroove 37 aR is an upward incline, and also the end portion 49 a of thepositioning shaft 49 is fit to the fitting groove 37 aR, and accordinglythe operating force exerted by the user at the time of mounting thecartridge tray 40 is great. However, the positioning shaft 49 enters thefitting groove 37 aR after the sliding face 46 d has moved beyond thepositioning shaft 50, and accordingly, the timing at which a greatoperating force is exerted by the user is not concentrated, and theoperating force can be reduced. Note that in this configuration, whenthe cartridge tray 40 is inserted as far as a predetermined distance tothe mounting position, the cartridge tray 40 is automatically taken upto the mounting position by a later-described take-up device.

When the cartridge tray 40 is inserted to the mounting position, and thefront door 31 (opening/closing member) is closed, the tray pressingunits 51 press the cartridge tray 40 to the deep side, as illustrated inFIGS. 14A, 15A, and 16A. The drum couplings 1 c on the driving side ofthe process cartridges PP and the developing couplings 3 c (see FIG. 3A)are engaged, and the pressing units 33 and 34 press the processcartridges PP from above.

FIGS. 18A through 19C are diagrams illustrating the pressing state ofthe pressing units 33 and 34 pressing the process cartridges. FIG. 18Ais a schematic perspective view partially cut along the longitudinaldirection of the photosensitive drums 1 with regard to a contact betweenthe main body developing contact 38 and the cartridge developing contact2 connected to the developing roller 3, and a contact between a pressingportion 33 a and a memory member 7, at the left side of the processcartridge PPK. FIG. 18B is a schematic diagram viewing the cut plane ofFIG. 18A in the direction of movement of the cartridge tray 40. FIG. 18Cis a schematic diagram viewing a cut plane of the process cartridges andthe cartridge tray 40 along a second imaginary plane IFL shown in FIG.18B, in the longitudinal direction of the photosensitive drums 1. FIG.19A is schematic perspective view partially cut along the longitudinaldirection of the photosensitive drums 1 with regard to the center of thedrum coupling 1 c at the right side of the process cartridge PPK. FIG.19B is a schematic diagram viewing the cut plane of FIG. 19A in thedirection of movement of the cartridge tray 40. FIG. 19C is a schematicdiagram viewing a cut plane of the process cartridges and the cartridgetray 40 along a first imaginary plane IFR shown in FIG. 19B, in thelongitudinal direction of the photosensitive drums 1.

Now, the pressing units 33 and 34 press the drum bearings 1 aL and 1 aRtoward the cartridge engaging portions 41 gL, 41 hL, 41 iL, 41 jL, 41gR, 41 hR, 41 iR, and 41 jR. The pressing unit 34 (first pressingmember) is disposed to intersect the first imaginary plane IFR that isorthogonal to the longitudinal direction of the photosensitive drums 1and intersects the cartridge engaging portions 41 gR, 41 hR, 41 iR, and41 jR (first positioning members). The pressing unit 33 (second pressingmember) is disposed to intersect the second imaginary plane IFL that isorthogonal to the longitudinal direction and intersects the cartridgeengaging portions 41 gL, 41 hL, 41 iL, and 41 jL (second positioningmembers).

Further, as viewed from the longitudinal direction of the photosensitivedrums 1, part of contact portions (pressing portions) 39 that areportions where the pressing units 33 and 34 come into contact with thecartridges are disposed overlapping the cartridge engaging portions 41gL, 41 hL, 41 iL, 41 jL, 41 gR, 41 hR, 41 iR, and 41 jR with respect tothe pressing direction of the pressing units 33 and 34. That is to say,the force of the pressing units 33 and 34 pressing the processcartridges is received by the cartridge engaging portions 41 gL, 41 hL,41 iL, 41 jL, 41 gR, 41 hR, 41 iR, and 41 jR that are on a straight linetherewith. Accordingly, the process cartridges can be strongly held andpositioned in a stable manner.

Further, the shaft supporting portions 41 dL and 41 dR and thepositioning grooves 41 bL and 41 bR of the tray side plates 41L and 41R,are provided on the same plane as the cartridge engaging portions 41 gL,41 hL, 41 iL, 41 jL, 41 gR, 41 hR, 41 iR, and 41 jR, and are supportedby the positioning shafts 49 and 50 (FIGS. 6A through 7B). Also, thepressing portions 33 a that are part of the contact portions 39 of thepressing unit 33 are also provided with contacts for the memory members7 provided to the process cartridges PP, for storing various types ofinformation such as operation history of the relevant process cartridge,performance information unique to the process cartridge, and so forth.By enabling strong holding and positioning of the process cartridges ina stable manner as described above, stable application of electricityand communication can be maintained.

Further, the pressing unit 33 is provided with main body chargingcontacts 37 for performing electric power supply to the charging rollers5, as illustrated in FIGS. 20A and 20B. The process cartridges PP havecharging contacts 6 electrically connected to the charging rollers 5.The main body charging contacts 37 are configured of wire members havingthe same configuration as the above-described wire members 48, and areconfigured to be biased against the charging contacts 6 by the springproperties thereof and come into contact with the charging contacts 6.FIGS. 20A and 20B are diagrams illustrating the positional relationbetween the power supply contact for electric power supply to thecharging roller 5, and the photosensitive drum 1 and the charging roller5 and so forth. FIG. 20A is a schematic perspective view illustratingthe contact of the main body charging contact 37 and the chargingcontact 6 partially cut along the longitudinal direction of thephotosensitive drum 1, at the left side of the process cartridge PPK.FIG. 20B is a schematic diagram viewing the cut plane in FIG. 20A in thedirection of movement of the cartridge tray 40. The pressing unit 33presses the process cartridges PP from above even at the portions wherethe main body charging contacts 37 are provided. The pressing unit 33presses the process cartridges PP from above, and also the main bodycharging contact 37 are positioned as to the charging contacts 6 of theprocess cartridges, thereby connecting the main body charging contacts37 and the charging contacts 6. The main body charging contacts 37 aredisposed at positions overlapping the photosensitive drums 1 and thecharging rollers 5 in the longitudinal direction of the photosensitivedrums 1. That is to say, the contact positions of the main body chargingcontacts 37 and the charging contacts 6 are disposed at positionsoverlapping the photosensitive drums 1 and the charging rollers 5 in thelongitudinal direction of the photosensitive drums 1. Accordingly, thecontact portions, the photosensitive drums 1, and the charging rollers 5can be each accurately positioned as to each other, by the pressing unit33 pressing in the proximity of the contacts of the main body chargingcontacts 37 and the charging contacts 6. That is to say, the processcartridges can be strongly held and positioned in a stable manner,whereby stable application of electricity can be maintained. Also, asturdy and stable contact path can be formed in the proximity of the endportions of the photosensitive drums 1 and the charging rollers 5, andaccordingly the contact paths within the process cartridges can beshortened, and the process cartridges can be manufactured inexpensively.Note that the main body charging contacts 37 and the charging contacts 6are disposed between the first supporting portion 41R1 and the secondsupporting portion 41L1 in the longitudinal direction of thephotosensitive drums 1.

As described above, after a state is entered in which the pressing units33 and 34 press the process cartridges from above, the main bodydeveloping contacts 38 come into contact with the cartridge developingcontacts 2 (see FIG. 3B) connected to the developing rollers 3, and thetransfer units 12 rotate upwards, centered on the driving rollers 14.Thus, the photosensitive drum 1 of each process cartridge comes intocontact with the intermediate transfer belt 13.

As described above, in a state in which the front door 31 is closed andthe printer 100 is capable of forming images, the positioning shaft 50and the positioning grooves 41 bL and 41 bR are engaged at the frontside of the cartridge tray 40. The inclined faces 41 f are provided tothe positioning grooves 41 bL and 41 bR, and accordingly at this time,the cartridge tray 40 is drawn inward in the insertion direction Y1 onthe basis of the own weight of the cartridge tray 40 and the downwardforce from the pressing units 33 and 34. Accordingly, the positioningfaces 41 e are pressed against the positioning shaft 50, and thecartridge tray 40 can be precisely positioned in the insertion directionY1.

Also, at the rear side of the cartridge tray 40, the positioning shaft49 and the positioning grooves 36 aL and 36 aR are engaged. At thistime, the end portions 49 a of the positioning shaft 49 fit into thefitting groves of the positioning grooves 36 aL and 36 aR, andaccordingly the cartridge tray 40 can be suppressed from rotating in adirection orthogonal to the mounting direction Y1, i.e., centered on thepositioning shaft 50.

The above positioning shaft 50 and the positioning grooves 36 aL and 36aR provided to the apparatus main body 100A, and the positioning grooves41 bL and 41 bR and the positioning shaft 49 provided to the cartridgetray 40, make up a positioning mechanism 60 (see FIGS. 11A and 11D). Thepositioning mechanism 60 positions the cartridge tray 40 as to theapparatus main body 100A.

Further, the positioning shaft 50 is supported from below by the rib 46b provided to the linking member 46 of the cartridge tray 40, wherebydownward deflection of the positioning shaft 50 is restricted. Also,deformation of the cartridge tray 40 itself is suppressed by theretaining portions 46 c provided to the linking member 46. Thepositioning shaft 49 at the back side of the cartridge tray 40 is alsosupported from below by the shaft contact portion 42 c, therebyrestricting downward deflection of the positioning shaft 49. Accordingto such a configuration, the positioning shafts 49 and 50 may be formedwith a smaller shaft diameter, or made from an inexpensive resinmaterial, and accordingly costs and size can be reduced.

According to these, the cartridge tray 40 can be precisely positioned asto the apparatus main body 100A at the mounting position. In particular,the process cartridges held in the cartridge tray 40 are pressed fromthe upper side by the pressing units 33 and 34 at the time of formingimages, but the precision of positioning of the cartridge tray 40 is notaffected. Accordingly, the precision of positions of the processcartridges held in the cartridge tray 40, specifically the positionalprecision between the photosensitive drums 1 and the intermediatetransfer belt 13 is improved, and high-quality images can be formed.

Also, due to the operations of the inclined faces 41 f at the front sideof the cartridge tray 40, and the pressing of the tray pressing units 51at the back side, the cartridge tray 40 is biased toward the front sidein the mounting position. Accordingly, positional deviation of thecartridge tray 40 due to vibrations and so forth at the time of formingimages can be reduced. Also, by generating force of pressing in at thefront and rear of the cartridge tray 40, the force of pressing inward isdispersed, and the elastic force of the biasing spring of the traypressing units 51 can be kept small. Accordingly, the size and cost ofthe tray pressing units 51 can be reduced.

According to the present invention, cartridges can be positioned to sideplates of the tray unit in a stable manner by the above configuration.

Also, according to the present invention, tray contacts of the tray unitto be electrically connected to cartridge contacts of cartridges can belaid out while conserving space.

Further, according to the present invention, guide grooves of the trayunit guided by the apparatus main body can be laid out while conservingspace.

Note that which of the apparatus main body 100A and the cartridge tray40 that the positioning shaft 50 and the positioning grooves 41 bL and41 bR included in the positioning mechanism 60 belong to may beswitched, as long as one is disposed in one and the other is disposed inthe other. Also, which of the apparatus main body 100A and the cartridgetray 40 that the positioning shaft 49 and the positioning grooves 36 aLand 36 aR included in the positioning mechanism 60 belong to may beswitched, as long as one is disposed in one and the other is disposed inthe other.

Also, the positioning shaft 49 is not limited to being a through shaftover the entire length of the cartridge tray 40 in the right-leftdirection. It is sufficient for two protrusions to be formed protrudingoutward to both sides of the cartridge tray 40.

Although the drum units OP and the developing units DP are integrallyformed in the process cartridges, these may be configured separately.The cartridge tray 40 may hold only the drum units OP, or hold only thedeveloping units DP, for example.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2020-136229, filed on Aug. 12, 2020, No. 2020-136143, filed on Aug. 12,2020, No. 2020-136209, filed on Aug. 12, 2020, which are herebyincorporated by reference herein in its entirety.

What is claimed is:
 1. An image forming apparatus comprising: acartridge including a first roller, and a roller contact electricallyconnected to the first roller; an apparatus main body including a mainbody contact, the main body contact configured to press the rollercontact; a mounting unit to which the cartridge is detachably mounted,the mounting unit including a first positioning portion and a secondpositioning portion, wherein the first positioning portion and thesecond positioning portion are configured to come into contact with thecartridge to position the cartridge as to an image forming position atwhich the image forming operation is performed, wherein a position atwhich the main body contact and the roller contact come into contact islocated between the first supporting portion and the second supportingportion in a longitudinal direction of the cartridge.
 2. The imageforming apparatus according to claim 1, the cartridge includes a secondroller configured to rotate about a rotation axis, wherein thelongitudinal direction is a direction parallel to a direction of therotation axis.
 3. The image forming apparatus according to claim 2, thesecond roller is a photosensitive drum.
 4. The image forming apparatusaccording to claim 3, the first roller is a charging roller configuredto charge the photosensitive drum.
 5. The image forming apparatusaccording to claim 2, the second roller is a developing roller.
 6. Theimage forming apparatus according to claim 5, the cartridge includes aphotosensitive drum, and wherein the first roller is a charging rollerconfigured to charge the photosensitive drum.
 7. The image formingapparatus according to claim 1, the position at which the main bodycontact and the roller contact come into contact overlaps a position ofthe first roller with respect to the longitudinal direction.
 8. Theimage forming apparatus according to claim 1, the apparatus main bodyincludes a pressing member configured to press the cartridge.
 9. Theimage forming apparatus according to claim 1, the cartridge includes acartridge end contact disposed at an end portion of the cartridge withrespect to the longitudinal direction.
 10. The image forming apparatusaccording to claim 9, further comprising: an end contact configured toelectrically connected to the cartridge end contact.
 11. The imageforming apparatus according to claim 10, wherein the apparatus main bodyincludes the end contact.
 12. The image forming apparatus according toclaim 1, wherein the main body contact configured to press the rollercontact from above the roller contact.
 13. The image forming apparatusaccording to claim 1, wherein the cartridge including a memory memberconfigured to store information, and the apparatus main body including apressing member including a memory contact, the pressing memberconfigured to press the memory member.
 14. The image forming apparatusaccording to claim 13, wherein the main body contact configured to pressthe roller contact from above the roller contact.
 15. The image formingapparatus according to claim 14, wherein the pressing member configuredto press the memory member from above the memory member.
 16. The imageforming apparatus according to claim 1, wherein the mounting unitincludes a first side plate including the first positioning portion, anda second plate including the second side positioning portion.
 17. Theimage forming apparatus according to claim 16, the first side plate ismade of metal.
 18. The image forming apparatus according to claim 17,the second side plate is made of metal.
 19. The image forming apparatusaccording to claim 1, wherein the mounting unit is configured to becapable of moving with respect to the apparatus main body, between aninternal position situated within the apparatus main body and anexternal position situated outside of the apparatus main body in adirection crossing to the longitudinal direction.
 20. The image formingapparatus according to claim 1, the mounting unit is a mounting unit towhich multiple cartridges are detachably attached, the multiplecartridges include the cartridge.